Furnace



Dec.3, 1929. IMMENNAN 1,738,254

FURNACE Filed June 1 1928 JWMIW (1% M QZW Patented Dec. 3, 1929 1,738,254

UiEn STATES PATENT OFFICE TEIJFORD MACLENNAN, OF HAMILTON, NEW ZEALAND FURNACE Application filed June 14, 1928, Serial No. 285,287, and. in New Zealand July 15, 1927.

This invention has been devised with the by any approved divisional member D, such ob ect of providing a construction of domesas will on each side, form with the tapering tic or other furnace that is designed to employ side of the casing, an inclined passage E lead a forced draught and therefore is made adaptmg into the top of the combustion chamber able to the burning of fine coal slack or other on that side.

low grade fuel, as the fuel for the fire. Conveniently the said dividing member D The invention consists in the construction may be a water boiler such as that shown in of the furnace with a bottom grate made so the drawings, having all the usual circulating that w iile allowing for the draught passing and supply connections and which by extend- 0 freely upward through it, it will serve to reing along above the combustion chamber will tain the fuel within the grate. The invention be heated by the tire therein. The underside also is concerned with provision for the autoof the boiler is concaved and at one end the matic supply of fuel to the fire, as consumpconcave space connects with a flue F leading tion takes place. from the back of the casing so that the prod- The invention comprises generally the comnets of combustion from the chamber B may bination with a furnace designed to be acted be collected and led off through the flue. upon by a forced draught, of inclined fuel The top of the casing being filled with finely supply passages that automatically feed the divided coal, such fuel will gravitate down fuel to the furnace, as that within it is conthrough both passages E into the chamber B 90 sumed. It also comprises the use within such beneath, as the fuel in such chamber is confurnace, of a fire grate constructed to support sumed, and thereby keep the chamber autoupon it finely divided fuel without liability matically supplied so long as a supply is of the fuel falling through and at the same maintained within the fuel supply chamber C. time to provide for the passage of the forced The furnace grate, as shown, is formed by a draught up through the grate over the whole plate G that is supported at the required 7 of its area. height within the casing A and is made with The invention may be given effect to in the longitudinal openings H, and fire bars J of manner shown in the accompanying drawings Z or T cross sectional shape, supported to exwhich illustrate a combined furnace and fuel tend along within or beneath such openings 30 supply passages embodying the features of so as to divide them up into a number of difthe invention. ferent slots each of which is underlaid at a In such drawing lower level by a member of the fire bars. This Fi r 1 i a lan f th d vice, arrangement leaves free air passages through Figure 2 is sectional plan of the lower or the grate, while preventing the fuel from fallfurnace portion thereof and taken on the line ing through it. 2-2 of Figure 3. The sides and ends of the grate may have Figure El is a cross sectional elevation of the fire-clay blocks K arranged thereon to concend viee trate the fire on to the middle portion of the Figure 4 is a side elevation thereof, half grate. Also the grate length may be divided being in section. into two by means of a fireclay block M ex- In the form of the invention shown the aptending along the middle line of the grate. paratus of the present invention comprises a These may however be dispensed with if so single metallic casing A of rectangular form desired. and so shaped as to provide a lower fuel com- The grate may also be formed in other ways bustion chamber B, and an upper fuel supply such as to ensure of the air passages of the chamber C of larger surface area than the nature described, being formed through the combustion chamber, the sides of which casing grate. A ta oer inwards and downwards to the sides The draught chamber, beneath the grate, is of the combustion chamber B. The fuel supenclosed and the forced air draught led into it ply chamber is divided throughout its length through the conduit N. Other ways of 0b 1 taining this updraught may however be provided.

It will be seen that by the construction shown, a furnace is produced that is suitable for the burning of finely divided coal fuel or slack, that needs no attention in the feeding of thefuel to thefireafter thesupply chamber is filled; that will burn freely by reasonof the forced draught and in addition, heat a supply of water if so desired.

I claim 7 if l. A furnace comprising a casing, a fire grate arranged in said casing, a domed member disposed in said casing above said grate and dividing the portion of said casing above sa d grate into-a f-uelsupplyvchamber-and-a fuel combustion chamber communicating with one'another, means for supplying-a cur- 'rentof air to the-under sideof saidgrate,

and means for withdrawing the gases of combustion. V furnace comprisinga hopper shaped casing, a firegrate arranged in the lower portion of said casing, a domed member disposed-in-saidcasing above said grate .and dividing the portion of saidcasing abovesaid gnate into a fuel supply chamber and a-'fuel combustion chamber, said "domed member having portions thereof spaced from the'si'de walls of said casing and forming therewith feed passages leadingw from-said fuel supply chamber to saidfuelcombustion chamber, meansfor supplying a current of air to the underside of saidgrate, and means for withdrawing the gases of combustion from-- said fuel combustionchamber.

' 3. A furnace comprisingsalhopper' shaped casing having tapering side alls, a tire; grate arranged in the: lower portion of said casing,

a hollow domedmemberdisposed in said casing above said grate and dividing the portion ofsaid casing above said-grate intoa fuelsupply chamber arnd a-fuel combustion. chamber, said domed member having side walls spaced from. theside walls of: said casing and forming therewithl inclinedfeed passages leading from said fuel supplychamber to said'fuel combustion chamber; means for supplying a current of:'-a-ir -to-the under side of said grate, said grate being adapted to'tpermit the passageof'air-but: to prevent the falling of f-uel theretlrrough, and means communicating withsaid fuel'combustion chambeffor with-V drawing the :gases' of combustion.

5A furnace. comprising, a hoppershaped casing, a: fire grate'arrangedin said casing, a :domed member disposed in said casing above said grate and dividing the portion-of said casing above'said; grate into a. fuel supply chamber above said member anda fuel 7 combustion chamber beneath said member,

said domed member having side walls spaced from thesi'deiwalls of saidrcasingand; forming :therewith feed vpassages lead-mg 1 from said supply chamber to said combustion In testimony whereof, I afiix my signature.

TELFORD MACLENNAN. 

